For example, a splice-site mutation in CHEK2 IVS2 + G > A has been found to be associated with breast cancer susceptibility in Poland (Cybulski et al. 2007), and the S428F allele of the CHEK2 gene increases breast cancer risk in Ashkenazi Jewish women (Shaag et al. 2005). Here, CHEK2 is linked to breast carcinoma.